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Bring Irregular Warfare to the Conventional Forces

In response to our peer and near-peer adversaries deploying irregular tactics against the U.S., many policymakers have sought to increase conventional forces’ training in irregular warfare (IW) tactics. Over the last six years, numerous directives and authorizations have attempted to broaden specialization in IW, ensuring that not only special operations forces (SOF), but the entirety of the conventional force, have competency in detecting and using IW. 

• The 2020 IW Annex to the National Defense Strategy directs the Department of Defense to “institutionalize irregular warfare as a core competency for both conventional and special operations forces.” 

• The 2022 National Defense Authorization Act discusses steps needed to “institutionalize the approach of the Department of Defense to irregular warfare and maintain a baseline of capabilities and expertise in irregular warfare in both conventional and special operations forces.”

• 2025 Pentagon directive DOD Instruction for Irregular Warfare (3000.07), released in September 2025, notes that IW is “a joint force activity conducted by conventional forces and special operations forces.”

According to retired U.S. Special Forces Lt. Col. Dr. Jeremiah Lumbaca, “none of the directives…have been implemented as intended.” Lumbaca also argues that based on a number of logistical constraints, “they will not be implemented anytime in the foreseeable future.”

The Special Operations Association of America (SOAA) has rounded up some of the arguments across the defense sphere for involving conventional forces in IW, and some of the impediments that would make this specialization incredibly difficult for a force trained in, and hailed for, its effectiveness in conducting large-scale combat operations (LSCO).

A Spectrum of Conflict

In a joint U.S. Army publication between the Irregular Warfare Center, The Irregular Warfare Initiative, the U.S. Army Irregular Warfare Proponent, and the U.S. Army Combined Arms Doctrine Directorate, authors cite the Defense Department definition of IW as “a form of warfare where state and non-state actors campaign to assure or coerce states or other groups through indirect, non-attributable, or asymmetric activities, either as a primary approach or in concert with conventional warfare.”

The authors argue that our adversaries will be more likely to “emphasize irregular approaches” as the U.S. increases its conventional lethality.

The authors note that some conventional elements already, in essence, perform an IW mission, including the Security Force Assistance Brigades (SFABs) that train up host nation forces in conventional warfare, and also “deter…adversarial aggression.”

In most cases, the authors say that “irregular approach options are less costly and typically incur risk to a smaller number of forces,” while giving leaders “flexibility” to “adjust the level of lethality over time as needed” and, hence, manage escalation. Contrarily, they explain that conventional warfare “often leads to rapid and uncontrolled escalation.”

To “mature and unify its irregular approach to joint campaigns,” the U.S. Army is working on doctrine that will include descriptions of Army forces “weav[ing] together irregular activities during competition, irregular warfare, and conventional warfare as part of joint campaigns.”

Irregular Warfare Isn’t New

U.S. Army Engineer Officer Austin Wesley supports including professional military education on IW for the conventional forces because he argues that the Army has failed to “institutionalize lessons learned from IW operations,” leaving it “reactive to irregular threats and often fail[ing] to achieve strategic objectives.”

Wesley points to the U.S. Army’s participation in Foreign Internal Defense (FID) during the Vietnam War, during which time it advised and assisted the South Vietnamese Army before becoming involved in LSCO against the North Vietnamese Army. During the phases of the conflict, “there was not a clean transition where one form of warfare stopped and another started,” Wesley argued.

With the advent of the Soviet threat, Wesley said that “most lessons from the war were quickly forgotten,” with “only SOF retain[ing] some institutional knowledge on IW.” As a result, he argued that the U.S. Army would relearn the lessons of Vietnam in Iraq when conventional forces were tasked with counterinsurgency operations, resulting in “significant resources, both blood and treasure, [being] expended unnecessarily.”

Retired Special Forces CW5 Chad Machiela and Seth Gray bring the discussion of U.S. employment of IW back even further to the American Civil War, when they describe how the Confederate Navy “commissioned ships in Britain using false names, civilian crews, and shell companies” to allow them to attack Union ships without attribution to the Confederacy.

Conventional Force Reward Structure

Lumbaca says that despite the appeal of preparing conventional forces for confronting “hybrid threats, proxy wars, and insurgencies” and operating “across the spectrum of conflict,” he argues that it would be “an exercise in futility” to expect that conventional forces can embrace IW. “Conventional military culture is defined by the pursuit of overwhelming kinetic advantage,” Lumbaca says. Success, and promotion, are tied to measures of “quantifiable destruction” and “tangible outcomes” that are not often available in IW operations that value ambiguity, and result in victory over “prolonged, often generational” efforts.

Furthermore, Lumbaca argues that because SOF was specifically intended to conduct IW, it “inadvertently grants conventional forces implicit permission to offload that responsibility.”

In training environments, Lumbaca says that conventional forces lack the time to integrate “meaningful IW training–which often requires language skills, cultural immersion, geographic specialization, and role-playing complex political scenarios.” 

To change conventional forces to accommodate the IW mission would require “a paradigm shift that clashes with deeply entrenched processes and vested interests,” Lumbaca says.

Retired U.S. Army Col. Alex Crowther told Breaking Defense that the promotion structure is a particular impediment to incorporating IW in the conventional forces. “How many general officers have been created, have been promoted, have been elevated to flag rank because of their skill, proficiency, and risk tolerance in the area of irregular warfare?” he asked. “I can’t think of a single one.”

Breaking the Cycle

If the U.S. does choose to make meaningful efforts to train conventional forces on IW, adaptations will be necessary.

Because of the “significant” training changes required “to shift from solely supporting large-scale combat operations to incorporating a mix of combat and non-combat activities that highlight intelligence, counterintelligence, psychological operations, and civil-military activities during competition and in preparation for conflict,” Sal Artiaga advocates for changes like including “real-world cases and simulations that reveal the intricate nature of IW settings,” and involving “case studies and historical analyses of past IW engagements.”

Wesley argues that professional military education (PME) should start early, and continue often. He argues against IW being taught solely by SOF elements because it “only reinforces the misperception that IW is exclusively a SOF mission.”

Dr. James W. Derleth proposes that with enemies increasingly “invested heavily in irregular warfare to exploit American vulnerabilities,” failing to educate conventional forces in IW “means that the Army will be unable to take a proactive posture or defeat irregular threats in multi-domain operations.”

Derleth noted that despite a training program already existing to deliver IW instruction to rotational training units (RTUs), “no RTU took advantage of this opportunity, citing the lack of training time.” Derleth argues that “this results in formations having limited or no practice identifying or defeating irregular tactics before their deployment to a [Combat Training Center] or to a real-world mission.”

Derleth, like others, worries that the Army “lacks a realistic exercise operational environment” to train in the identification or employment of irregular tactics, leading to a “myopic focus on conventional threats” that “obscures the complexity of irregular threats.”

“How do we defeat multi-domain irregular tactics in the gray zone?” Derleth asks. “One thing is clear: long-range precision fires, tank divisions, improved air defense, and other high-end technologies will not prevent or defeat them. For the Army to be able to fight and win our nation’s wars, it must be educated and trained to identify and defeat irregular warfare tactics. In other words, we must train as we would fight.”